Diuris septentrionalis, commonly known as northern bee orchid, is a species of orchid that is endemic to the south-west of Western Australia. It has two or three linear leaves and up to five yellow flowers with dark red markings.
Diuris septentrionalis is a tuberous, perennial herb with two or three linear leaves long and wide. Up to five yellow flowers with dark red markings, long and wide are borne on a flowering stem tall. The dorsal sepal is tapering egg-shaped to elliptic, long and wide. The sepals are parallel or crossed near the tip, long, wide and project forwards. The petals are paddle-shaped, the blades elliptic to egg-shaped or round, long and wide on a reddish-brown stalk long. The labellum is long with three lobes - the centre lobe broadly wedge-shaped to heart-shaped, long and wide. The side lobes spread widely apart and are oblong, long and wide. There are two smooth calli ridges outlined with red near the mid-line of the labellum. Flowering occurs in August and September.
Diuris septentrionalis was first formally described in 2013 by David Jones and Christopher J. French in Australian Orchid Review, from a specimen collected by French in 2001. The specific epithet (septentrionalis) means "north" or "northern", referring to the distribution of the species.
Northern bee orchid grows in winter-wet shrubland between Regans Ford and areas inland from Kalbarri in the Avon Wheatbelt, Geraldton Sandplains, Jarrah Forest, Swan Coastal Plain bioregions of south-western Western Australia.
Diuris septentrionalis is listed as "not threatened" by the Western Australian Government Department of Biodiversity, Conservation and Attractions.